Research


Research Projects


Baldwin Creek in Davenport, CA.

Alyssa Schaer, project collaborator, retrieves week one of four leaf packs to measure weekly decomposition rates and to detect invasive New Zealand Mud Snails.

Honors capstone project – The influence of salinity on leaf-litter breakdown rates in tidal streams

Principal Investigator: John R. Olson, Ph.D.

Dates: October 2020 – Present

Location: Our study areas are eight tidal streams and associated estuaries in central California.

Project description: I’m investigating the rate of leaf-litter breakdown by microbes in brackish water. Alyssa Schaer is looking at leaf-litter breakdown by aquatic invertebrates and using leaf packs as a method to detect invasive snails.

Skills: In first round of data collection, Dr. Olson and I deployed 16 leaf packs and 8 conductivity/temperature data loggers. In May 2020, Alyssa Schaer came on board the project. We deployed 16 more leaf packs in tidal streams but this time picking up one leaf pack per week. We aim to better understand how to calculate decomposition rates (weight lost/number of days in the river). This will hopefully clarify if most of the decomposition is happening in the first two weeks rather than evenly across one month. Alyssa is assessing leaf packs as a method for detecting invasive New Zealand Mud Snails using the same samples.

Field crew: Alyssa Schaer, Alexus Cobarrubias and Dr. John Olson.


Sprinkler system simulating rainfall over the riparian zone at Kings Creek.

Molly Fisher, masters candidate, filling a water tank with deionized spring water. This will supply water to the sprinkler system.

Dr. Walter Dodds and I collecting soil water from miniature lysimeters in the riparian zone before the rainfall simulation.

James Guinnip, PhD candidate, filtering stream water samples for dissolved nutrient analysis. 

Lane Lundeen filtering the water samples to determine the concentration of suspended sediments.

Research Experiences for Undergraduates (REU)

Hosted by the NSF Microbiomes of Aquatic, Plants, and Soil Systems across Kansas (MAPS) Project

Project: Assessing transport and retention of nitrate and other materials through the riparian zone and stream channel with simulated precipitation.

Principal Investigator: Walter K. Dodds, Ph.D.

Dates:  April 2020 – Present

Location: Kings Creek is our experimental site, located on the Konza Prairie Biological Station also home to the NSF-funded Konza LTER.

Project description: Originally, a rainfall simulation experiment over the riparian zone was conducted by Brittany Kirsch for her master’s thesis at the University of Nebraska-Lincoln. The Dodds Lab expanded this experiment design by adding 15NO3– isotopic tracer and NaBr conservative solute to our “rainwater” to track flow paths.

Skills: I lead the field experiment by managing over 250 samples and creating a coordinating data collection form. James Guinnip played a large role in my REU because he taught me the Lotic Intersite Nitrogen eXperiment (LINX II) protocol for measuring isotopic enrichment of dissolved inorganic nitrogen. In the field, Dr. John Blair helped us take soil cores and deploy miniature lysimeters. Molly Fisher and I managed large field equipment such as a portable deionization system, 250 gallon tank, and sprinkler operation. Lane Lundeen and I filtered total suspended solid samples. Shaun Baughman helped with the LINX II protocol and processed riparian soil and grass samples.

Field crew: Dr. Walter Dodds, Dr. John Blair, James Guinnip, Dolly Gudder, Anne Schechner, Molly Fisher, Justin Brisendine, Alex Wohler, and Lane Lundeen.


On-going Fieldwork


Lexi Yokomizo, new field crew leader, measuring river discharge in Lower San Clemente Creek on the Santa Lucia Preserve.

Hydrology monitoring for the Santa Lucia Conservancy.

Principal Investigator: John R. Olson, Ph.D.

Dates: August 2018 – Present

Location: The Santa Lucia Conservancy in Monterey, California.

Project description: The fieldwork for this ten year long monitoring project collects data for annual reports written by various Master’s students in our lab.

Skills: For the past two years I lead the field portion of monthly hydrology monitoring, biannual water chemistry monitoring, and annual creek walks. Now, Lexi Yokomizo is leading monthly monitoring and learning the ropes of biannual monitoring and creek walks. I check the data entry and provide knowledge transfer when needed.

Field crew: Lexi Yokomizo, Kelsey Trammell, Alyssa Schaer, Janelle Vasquez, and Madison McCarty.


Fieldwork Stints


Intercalibration between field team Kat Nickel and Jess Turner and field team Madison McCarty and I in Colorado.

Madison McCarty collecting aquatic invertebrates from slow and fast water benthic stream habitats.

Me downloading HOBO logger pendant data. This logger records stream temperature and conductivity to characterize stream intermittency.

Streamflow duration assessment in the central Rocky Mountains for the Environmental Protection Agency (EPA).

Principal Investigator: John R. Olson, Ph.D.

Dates: July 6 – 30, 2020 and July 3 -18, 2021

Location: We traveled across the central Rocky Mountains visiting Colorado, Wyoming, and Utah.

Project description: The combination of streamflow loggers and sites visits are used to classify streams as perennial, intermittent, or ephemeral. We followed the same protocol as other field crews across the US. In the Esri Survey123 App we reported hydrological, geomorphological, and biological streamflow indicators for 52 sites. Dr. John Olson’s field crews have covered the western coasts and mountains region. The Environment Protection Agency is invested in the findings to inform the Clean Water Act.

Skills: My field partner Madison McCarty and I divided the site assessment into two roles. I identified hydrophytic vegetation, retrieved and deployed the HOBO logger and uploaded the pendant data onto a laptop, quantified vegetative cover using a densiometer, and managed the Survey123 app. Madison collected aquatic invertebrates and exuviae, identified soil moisture and texture, and checked for hydric soils. Together we assessed stream structure such as floodplain connectivity, sinuosity, and stream substrate sorting.

Field crew: Madison McCarty and remote communication with Dr. John Olson.


Kelsey Trammell measuring stream depth.

Me recording the location of a pool habitat unit.

Kelsey Trammel and I using a FlowTracker to calculate stream discharge. In the background, there is a vertical piece of cement showing where the San Clemente Dam stood from 1921 to 2015.

Ecological monitoring of the Carmel River reroute following the San Clemente Dam removal.

Principal Investigator: John R. Olson, Ph.D.

Dates: June 28 – 30, 2020 

Location: We surveyed the Carmel River reroute in Monterey, California. we surveyed habitat units and classified stream channel type.

Project description: This survey assesses habitat units and classifies stream channel type. The third year of this five year monitoring project tracks shifting habitat for steelhead trout fish passage.

Skills: We rotated the three field roles of recorder, depth measurer, and GPS coordinate tracker. At each habitat unit, the recorder assessed shelter value, bank vegetation and composition, exposed substrate, woody debris, and habitat unit type after consulting with the team. The depth measurer noted dominant substrate composition, number of steelhead year of the young, and three depth measurements. The GPS coordinate tracker noted three rangefinder measurements for wetted width, densiometer reading, and GPS coordinate as well as a photo at the bottom of the unit. The Rosgen (1994) stream channel typing method included two people holding stadia rods and the third person using a level from a hill.

Field crew: Dr. John Olson and Kelsey Trammell.


A chorus frog in a wetland.

Frog eggs in a small pond.

Me removing a filter to store in a falcon tube. This site is a wetland on Vandenberg Airforce Base in Lompoc, California.

Environmental DNA (eDNA) collection to detect amphibian species on Department of Defense (DoD) land.

Principal Investigator: John R. Olson, Ph.D.

Dates: March 28 – 31 and April 18 -20, 2019

Location: Field methods were conducted across DoD land in California. Specifically at Vandenberg Airforce Base, Camp Hunter Liggett, Camp Roberts, Camp San Luis Obispo, and Los Padres National Forest.

Kat Hicks and I visited Los Padres National Forest and Vandenberg Airforce Base.

Project description: The eDNA samples were collected at over 100 sites by about 20 field crew member. The samples were sent to Utah State University for analysis. The data will be used to create empirical models which will predict the distributions of threatened amphibian species. The findings will inform DoD conservation strategies.

Skills: In preparation for fieldwork, I assisted in decontaminating and assembling eDNA collection kits. In the field, we assembled a three-part water pump that is used for pumping 5 liters of water through a filter. The filter is then stored in a falcon tube. We deployed a YSI multiprobe to record water quality parameters. The surrounding land use was briefly surveyed and recorded.

Field crew: Kat Hicks and remote communication with Dr. John Olson.


High School Research Assistantship


Eelgrass bed community in southern California. Photo credit: SCCWRP.

Small marine invertebrates under a microscope. This sample was collected from an eel grass community in Mission Bay.

Impacts of copper contamination and habitat degradation on eelgrass (Zostera marina) mesograzers.

Principal Investigator: Kevin Hovel, Ph.D.

Dates: Summer 2017 – Spring 2018

Location: The lab work was conducted at San Diego State University (SDSU) Coastal and Marine Institute. The fieldwork was conducted in Mission Bay in San Diego, California.

Project description: Kyra Barboza‘s masters thesis involved assessing the effects of copper contamination on eelgrass communities.

While I was in high school, I was Kyra Barboza’s main research assistant for completing lab and field work to support her master’s thesis.

Skills: I assisted master’s candidate Kyra Barboza by running water quality trials on kelp fish and grass shrimp, identifying marine invertebrates, and processing chlorophyll samples from eelgrass beds. We collected kelp fish and grass shrimp from Mission Bay using a sein and kick nets.

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